Question

8. Here we are going to consider the differences between spectra and chromatograms. A list is given below of characteristics and behaviors of UV spectra and liquid chromatography. Some characteristics listed apply only to spectra. Other characteristics apply only to chromatography. And here’s the tricky bit, some characteristics apply to both. From the list below enter each characteristic that is correct for that instrumental plot on the line associated with that instrumental plot. Be careful, think about your choices, misplaced characteristics are negative points.

1. Usually has molar absorptivity values reported in homogeneous liquid solution

2. In our work in this lab, the solvent system is the eluent

3. Spans the UV and visible regions of the electromagnetic spectrum

4. Can be used for analytical work

5. Displays radiation absorption by molecules in solution

6. Displays the retention/separation by an appropriate stationary phase of molecules in solution

7. Provides information about how molecules are distributed between mobile and stationary phases

8. Can be used to identify unknown components in samples

9. Has time as the independent variable on the detector output plot

10. Has wavelength as the independent variable on the detector output plot

11. Has absorbance as the dependent variable on the output plot

12. Is concerned with electronic transitions in molecules

13. Is concerned with molecular distribution between phases

14. May show the instrument output plot at a constant flow rate

A. Liquid Chromatography plot characteristics are: _______________

B. UV spectral plot characteristics are: ________________

Answer 1

A. Liquid Chromatography plot characteristics are: _______________

1. Usually has molar absorptivity values reported in homogeneous liquid solution
2. In our work in this lab, the solvent system is the Eluent
3. Displays the retention/separation by an appropriate stationary phase of molecules in solution
4. Provides information about how molecules are distributed between mobile and stationary phases
5. Can be used to identify unknown components in samples
6. Is concerned with molecular distribution between phases
7. May show the instrument output plot at a constant flow rate

B. UV spectral plot characteristics are: ________________

1. Spans the UV and visible regions of the electromagnetic spectrum
2. Can be used for analytical work
3. Displays radiation absorption by molecules in solution
4. Has wavelength as the independent variable on the detector output plot
5. Has absorbance as the dependent variable on the output plot
6. Is concerned with electronic transitions in molecules
7. Has time as the independent variable on the detector output plot